The invention relates to the field of shoes. In particular, the invention describes a method and an apparatus for incorporating a medial/lateral counter foot stabilizer in shoes.
During their lifetimes, approximately 60% of all people will have a foot problem of sufficient importance to cause discomfort and/or pain. Most minor foot problems are discussed with amateurs, such as shoe salespersons. More serious problems are referred to primary care physicians or orthopedists. Ideally, pedorthic management begins with an evaluation of footwear and foot support. Regardless of whether a foot problem is minor or substantial, the foot and shoe must work together as a unit, with the shoe providing proper alignment and support of the foot.
There are numerous syndromes that can be caused by misalignment of the calcaneus (heel bone). For example, neuromas are an enlargement of an intermetatarsal nerve sheath. Neuromas usually occur in the space between the third and fourth toes and metatarsals (the third metatarsal space), and are often caused, at least in part, by excessive foot pronation. Shin splints may be caused by tears in the anterior or medial tibial muscles. Anterior shin splints (along the front of the shin) are often associated with repetitive traction of the muscles or repetitive loading with excessive stress, and are usually the result of an imbalance between anterior and posterior tibial muscles. Medial shin splints (along the inside shin) are usually caused by excessive exercise. Both anterior and medial shin splints are exacerbated by excessive pronation. Excessive pronation can also cause calluses and heel spurs.
There are also numerous problems caused by insufficient arch support. For example, lack of support in the medial arch (the main arch along the inside of the foot) can lead to foot fatigue, plantar fasciitis (heel spurs), neuroma pain, or bunions. Lack of support in the metatarsal arch (under the ball of the foot) can cause metatarsalgia (a pain in the ball of the foot), pain in the toes, or decreased balance control. Supporting the lateral arch (on the outer side of the foot) aids in balance and posture, and provides side-to-side stability.
Orthotic inserts have been described for cushioning of the calcaneus or providing arch support. For example, U.S. Pat. No. 4,235,028 describes a heel pad for an athletic shoe having an aperture which cushions the heel, and U.S. Pat. No. 4,137,654 describes an insert which provides a heel cup with a horizontally extending wedge having a decline of 4 to 5 degrees to reduce pronation and supination of the heel. Also, U.S. Pat. No. 4,882,856 describes an insert (and shoes) with a wedge-shaped cushion which has greater resiliency than the remainder of the insert, and is positioned to reduce heel pronation/supination. These inserts generally provide for an elevated heel cushion, and do not provide support for the lateral, medial or metatarsal arches.
U.S. Pat. Nos. 4,718,179 and 5,394,626 describe orthotic inserts which are custom-molded to a patient""s foot. The inserts described in these patents utilize a cloth-like padded sole attached to a more rigid elevated heel cap, require elevated lateral and medial stabilizers as a means to elevate the heel, and do not provide significant lateral side-wall support for the heel cap. Similarly, U.S. Pat. No. 4,439,934 (Re 32,698) also describes a two-piece insert utilizing a cloth-like upper attached to a more rigid elevated heel and mid-sole, but requires the mid-sole/heel portion to be generated using layers of fiberglass resin. U.S. Pat. Nos. 4,597,196 and 6,070,342 also describe multipart insole assemblies for a shoe. U.S. Pat. No. 4,597,196 describes an orthotic custom-fitted to a patient""s foot and having a flexible (cloth-like) padded upper blank, a relatively rigid cap extending from the heel to the metatarsal region, a moldable, cushion insert between the upper and the blank surrounding the perimeter of the heel, and a pad to cushion the heel and midsole. U.S. Pat. No. 6,070,342 describes an insert having a cloth-like upper attached to a more rigid, U-shaped elevated heel and mid-sole, which has first and second flanges along the lateral and medial side portions to support an elevated heel. Thus, the inserts described in these patents each require a multipart construction using a relatively raised heel cap with a padded upper sole, and do not provide extensive medial and lateral constriction of the heel to control pronation and supination, but are more concerned with conforming closely to the plantar surface of an individual foot.
U.S. Pat. No. 6,141,889 describes a foot support having a plurality of non-parallel grooves and ridges based upon a scan of an individual foot, and U.S. Pat. No. 4,674,206 describes a midsole construction insert which utilizes an air cushion and an elastomeric resin for support of the foot. U.S. Pat. No. 6,029,374 describes a midsole system for a shoe having a sole spring, a heel spring and/or forefoot springs for a running shoe. Thus, these patents are primarily concerned with providing arch support, but do not control pronation/supination of the heel.
Finally, U.S. Pat. No. 3,058,240 describes a shoe which is designed from the sole up, to cling to the rear portion of the foot so that transverse constriction of the foot is unnecessary. The shoe of U.S. Pat. No. 3,058,240 is made of moisture pervious material so that it can hug the heel and arches with a glove-like clinging fit.
None of the previous art describes using a medial/lateral counter stabilizer to augment commercially manufactured shoes to provide increased arch support and heel alignment. Nor is there described a medial/lateral counter stabilizer comprising a full plantar aspect, a counter, lateral side wall support, and support of the metatarsal, medial and lateral arches, as a single unit.
Thus, there is a need for a foot stabilizer that provides both arch support and heel alignment in commercial shoes, and can be produced for integration as a part of a shoe to provide a shoe with superior control of calcaneal position and arch support. The stabilizer should be light-weight and of a simple design so that it may be adapted for most shoe types. The stabilizer should be designed to provide a preferred conformation for feet of different shapes and sizes. Additionally, the stabilizer should be designed to position the foot properly throughout the gait cycle. By providing arch support and controlling pronation and supination of the foot, a foot stabilizer controls subtalar joint motion and encourages plantar grade position during the gait. Shoes having medial/lateral counter foot stablizers are expected to help manage a variety of foot conditions including plantar fasciitis, pes planus, pes cavus, old fracture sites, hallux rigidus, lateral ankle sprains, metatarsalgia, bursitis, and plantar warts.
In one aspect, the invention comprises an orthotic stabilizer for a shoe comprising a plantar aspect which extends substantially the length of the sole of the shoe, a lateral side wall extending from at least a part of the plantar aspect, a medial wall extending from at least a part of the plantar aspect, and a heel cup counter.
In another aspect, the invention comprises a method of reducing foot and leg injury comprising integrating a lateral/medial counter foot stabilizer into a shoe, wherein the stabilizer comprises a plantar aspect which extends substantially the length of the sole of the shoe, a lateral side wall extending from at least a part of-the plantar aspect, a medial wall extending from at least a part of the plantar aspect, and a heel cup counter.
In another aspect, the invention comprises a method of reducing foot and leg injury comprising preventing heel misalignment and providing support for the lateral, medial and metatarsal arches.
In yet another aspect, the invention comprises a method for reducing foot and leg injury comprising integrating an orthotic stabilizer into a shoe, wherein the stabilizer is custom-molded to provide orthotic treatment to an individual foot, and wherein the stabilizer comprises a plantar aspect which extends substantially the length of the sole of the shoe, a lateral side wall extending from at least part of the plantar aspect, a medial wall extending from at least part of the plantar aspect, and a heel cup counter.